Structure for fixing light guiding member

ABSTRACT

A structure for fixing a light guiding member includes a light guiding member that guides light emitted from a light source to a prescribed position, a holder that holds the light guiding member, and a fixed member fixed to the light guiding member. The holder includes an insertion hole through which the light guiding member is inserted. The light guiding member includes a flange larger in outer geometry than the insertion hole and a shaft portion connected to the flange and inserted through the insertion hole. The fixed member is fixed to a portion of the shaft portion that projects from the insertion hole and larger in outer geometry than the insertion hole.

This nonprovisional application is based on Japanese Patent ApplicationNo. 2020-006125 filed with the Japan Patent Office on Jan. 17, 2020, theentire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION Field of the Invention

This disclosure relates to a structure for fixing a light guidingmember.

Description of the Background Art

An illumination apparatus including a light guiding member hasconventionally been known. For example, Japanese Patent Laying-Open No.2011-51500 discloses an illumination apparatus including an LED lamp, alens, a case, and a garnish. The case is provided with an engagementpawl and the lens is provided with an engagement hole. As the engagementpawl is engaged with the engagement hole, the lens is fixed to the case.An engagement pawl is erected on the lens. As the engagement pawl isengaged with a pawl receiver formed in the garnish, the lens is fixed tothe garnish.

SUMMARY OF THE INVENTION

The illumination apparatus described in Japanese Patent Laying-Open No.2011-51500 is structured such that the lens is fixed by engagementbetween the engagement pawl and the engagement hole. Therefore, there isa concern about detachment of the lens from the case or the like due tovibration or the like.

An object of the present disclosure is to provide a structure for fixinga light guiding member, the structure allowing suppression of detachmentof a light guiding member from a holder.

A structure for fixing a light guiding member according to thisdisclosure includes a light guiding member that guides light emittedfrom a light source to a prescribed position, a holder that holds thelight guiding member, and a fixed member fixed to the light guidingmember. The holder includes an insertion hole through which the lightguiding member is inserted. The light guiding member includes a flangelarger in outer geometry than the insertion hole and a shaft portionconnected to the flange and inserted through the insertion hole. Thefixed member is fixed to a portion of the shaft portion that projectsfrom the insertion hole and is larger in outer geometry than theinsertion hole.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view schematically showing arrangementrelation between a license lamp and a license plate in one embodiment ofthe present disclosure.

FIG. 2 is a perspective view of the license lamp shown in FIG. 1.

FIG. 3 is a front view of the license lamp shown in FIG. 2.

FIG. 4 is a cross-sectional view along the line IV-IV shown in FIG. 3.

FIG. 5 is a cross-sectional view along the line V-V shown in FIG. 3.

FIG. 6 is a perspective view of a holder of the license lamp.

FIG. 7 is an enlarged view of an area shown with a solid line VII inFIG. 6.

FIG. 8 is a perspective view of a lens.

FIG. 9 is a perspective view of the lens at an angle different from theangle in FIG. 8.

FIG. 10 is a plan view of the lens and a light source.

FIG. 11 is a cross-sectional view along the line XI-XI shown in FIG. 10.

FIG. 12 is a cross-sectional view along the line XII-XII shown in FIG.10.

FIG. 13 is a diagram schematically showing an exemplary path of outgoinglight.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present disclosure will be described with referenceto the drawings. The same or corresponding members in the drawingsreferred to below have the same reference characters allotted.

FIG. 1 is a cross-sectional view schematically showing arrangementrelation between a license lamp and a license plate in one embodiment ofthe present disclosure. FIG. 2 is a perspective view of the license lampshown in FIG. 1. FIG. 3 is a front view of the license lamp shown inFIG. 2. FIG. 4 is a cross-sectional view along the line IV-IV shown inFIG. 3. FIG. 5 is a cross-sectional view along the line V-V shown inFIG. 3.

A license lamp 1 in the present embodiment is an apparatus thatilluminates a license plate 20. As shown in FIG. 1, license plate 20 isattached, for example, to a back door 10 of a vehicle. License plate 20is attached to back door 10 in such a position that a longitudinaldirection thereof is in parallel to a width direction of the vehicle (adirection of depth of the sheet plane in FIG. 1). License lamp 1 isfixed above a portion of back door 10 where license plate 20 isattached.

License lamp 1 includes two light sources 100, two lenses 200, a holder300, two fixed members 400, and two switches 500.

Light source 100 serves to illuminate license plate 20. In the presentembodiment, a light emitting diode (LED) is adopted as light source 100.Each light source 100 is mounted on a substrate 150 (see FIG. 1).

As shown in FIG. 1, substrate 150 is arranged in holder 300 in such aposition that light emitted from each light source 100 travels towardlicense plate 20 located below light source 100.

Lens 200 is a member that diffuses outgoing light L1 (see FIG. 13)emitted from light source 100. Lens 200 diffuses outgoing light L1mainly outward in a direction orthogonal to an optical axis L0 ofoutgoing light L1 (the longitudinal direction of license plate 20). Lens200 in the present embodiment particularly performs a function todiffuse light at a relatively small angle with respect to optical axisL0 of outgoing light L1 (high-luminance light in the vicinity of opticalaxis L0), outward in the direction orthogonal to optical axis L0. Lens200 functions as a light guiding member that guides outgoing light L1 toa prescribed direction. Lens 200 is made of acrylic. Lens 200 includes adiffuser 210, a flange 220, and a locking portion 230.

Diffuser 210 is a portion that diffuses outgoing light L1. Diffuser 210is formed like a shaft. Diffuser 210 includes an incident surface 211and an emission surface 212.

Incident surface 211 is a surface through which outgoing light L1 enterslens 200. Incident surface 211 is formed at a position opposed to lightsource 100. Incident surface 211 refracts outgoing light L1 outward inthe direction orthogonal to optical axis L0 (a lateral direction in FIG.11), with respect to optical axis L0 of the outgoing light.Specifically, as shown in FIGS. 4 and 11, incident surface 211 is in ashape convexly curved toward emission surface 212 (in a direction awayfrom light source 100).

Incident surface 211 includes an end incident portion 211 a. Endincident portion 211 a is formed at opposing ends in an orthogonaldirection (the lateral direction in FIG. 10) orthogonal to a directionof connection between incident surface 211 and emission surface 212. Asshown in FIGS. 8 and 10, end incident portion 211 a is in a shape curvedconvexly inward in the orthogonal direction.

Emission surface 212 is a surface where incident light L2 (see FIG. 13)incident on incident surface 211 exits from lens 200. Emission surface212 is formed from a surface of diffuser 210 opposite to incidentsurface 211. Emission surface 212 refracts incident light L2 outward ina direction orthogonal to a centerline of incident light L2, withrespect to the centerline of the incident light. Specifically, as shownin FIGS. 4 and 11, emission surface 212 is in a shape convexly curved ina direction away from incident surface 211. Emission surface 212 issmaller in curvature than incident surface 211. Emission surface 212includes a main surface. An incident angle of incident light L2 withrespect to the main surface is set to a critical angle (approximately 42degrees in the present embodiment).

Flange 220 is in a shape protruding outward from a tip end (a lower endin FIG. 11) of diffuser 210 in a direction from incident surface 211toward emission surface 212 (downward in FIG. 11). A direction fromincident surface 211 toward emission surface 212 is denoted as a “lighttravel direction” below. As shown in FIGS. 8 and 10, flange 220 isformed in an annular shape continuous in a circumferential direction ofdiffuser 210. Flange 220 includes an inner annular portion 220 a, apressing portion 220 b, and an outer annular portion 220 c.

Inner annular portion 220 a is formed on a surface (an upper surface inFIG. 11) of flange 220 in a direction opposite to the light traveldirection (downward in FIG. 11). Inner annular portion 220 a is in ashape protruding outward from an outer circumferential surface ofdiffuser 210 and surrounding diffuser 210. Inner annular portion 220 ais formed as being flat.

Pressing portion 220 b is in a shape protruding outward from an outerperiphery of inner annular portion 220 a and surrounding inner annularportion 220 a. As shown in FIGS. 11 and 12, pressing portion 220 b is ina shape inclined in the light travel direction as it is more distantfrom inner annular portion 220 a.

Outer annular portion 220 c is in a shape protruding outward from anouter periphery of pressing portion 220 b and surrounding pressingportion 220 b. Outer annular portion 220 c is formed as being flat.

Locking portion 230 is provided in the outer circumferential surface ofdiffuser 210. Locking portion 230 is a portion where fixed member 400 islocked. In the present embodiment, locking portion 230 is in a shapeprojecting outward from the outer circumferential surface of diffuser210.

Holder 300 is a member that holds light source 100 and lens 200. Holder300 holds light source 100 and lens 200 such that outgoing light L1enters incident surface 211 and illumination light L3 that exits fromemission surface 212 illuminates license plate 20.

Holder 300 includes an insertion hole 300 h through which diffuser 210is inserted. Holder 300 holds lens 200 while diffuser 210 is located ininsertion hole 300 h. Namely, diffuser 210 forms a shaft portioninserted through insertion hole 300 h. Flange 220 is larger in outergeometry than insertion hole 300 h. Holder 300 and lens 200 define anaccommodation space. Light source 100, substrate 150, switch 500, andthe like are arranged in the accommodation space.

Holder 300 includes a low rigidity portion 310 and a high rigidityportion 320.

Low rigidity portion 310 is made, for example, of thermoplasticelastomer. Low rigidity portion 310 includes a flange receiving portion312, a holding portion 314, an adjacent portion 316, and an operationportion 318.

Flange receiving portion 312 is a portion that receives flange 220. Asshown in FIG. 7, flange receiving portion 312 includes an innerreceiving portion 312 a, an annular rib 312 b, and an outer receivingportion 312 c.

Inner receiving portion 312 a receives inner annular portion 220 a.Inner receiving portion 312 a is formed in an annular shape thatsurrounds insertion hole 300 h. Inner receiving portion 312 a is formedas being flat.

Annular rib 312 b is in a shape erected from an outer periphery of innerreceiving portion 312 a and surrounding inner receiving portion 312 a.Annular rib 312 b is in a shape surrounding the entire circumference ofinsertion hole 300 h and projecting toward flange 220.

Outer receiving portion 312 c is in a shape protruding outward from anouter periphery of annular rib 312 b and surrounding annular rib 312 b.Outer receiving portion 312 c is formed as being flat. As shown in FIG.13, a distance between outer receiving portion 312 c and the top ofannular rib 312 b is longer than a distance between inner receivingportion 312 a and the top of annular rib 312 b. Namely, outer receivingportion 312 c is formed at a position that retracts from inner receivingportion 312 a in a direction opposite to the light travel direction.Therefore, a space allowing tilt of annular rib 312 b is defined betweenouter receiving portion 312 c and outer annular portion 220 c.

Holding portion 314 defines a part of insertion hole 300 h. Holdingportion 314 holds diffuser 210 as being in intimate contact with theouter circumferential surface of diffuser 210. In other words, diffuser210 is pressed into holding portion 314. A gap between holding portion314 and diffuser 210 is thus sealed. Holding portion 314 holds diffuser210 as being in intimate contact with the outer circumferential surfaceof diffuser 210 so as to maintain a state that pressing portion 220 bpresses annular rib 312 b (a state that annular rib 312 b is in intimatecontact with pressing portion 220 b). Namely, the gap between lens 200and holder 300 is sealed at two points.

Adjacent portion 316 defines the remainder of insertion hole 300 h.Adjacent portion 316 is formed at a position adjacent to holding portion314 in an axial direction of diffuser 210. Adjacent portion 316 definesa space between adjacent portion 316 and the outer circumferentialsurface of diffuser 210. The space accepts a part of holding portion 314that deforms at the time of pressing of diffuser 210 into holdingportion 314. The tip end of adjacent portion 316 in the light traveldirection is continuous to an inner end of inner receiving portion 312a.

Adjacent portion 316 does not have to be provided. In this case, holdingportion 314 forms the entire portion that defines insertion hole 300 h.

Operation portion 318 is a portion for operating switch 500. As shown inFIG. 1, operation portion 318 is formed at a position adjacent toholding portion 314.

Switch 500 is arranged at a position where pressing of operation portion318 can be sensed. Switch 500 is operated to open back door 10. As shownin FIG. 1, switch 500 is mounted on a substrate 550. Substrate 550 isarranged in the accommodation space.

High rigidity portion 320 is higher in rigidity than low rigidityportion 310. High rigidity portion 320 is made, for example, ofpolypropylene. As shown in FIGS. 4 and 5, high rigidity portion 320supports a part of low rigidity portion 310 from an inner side thereof.In other words, the surface of high rigidity portion 320 is covered withlow rigidity portion 310. High rigidity portion 320 is formed integrallywith low rigidity portion 310 by two-color molding or the like. Highrigidity portion 320 supports a portion of low rigidity portion 310other than holding portion 314 and operation portion 318.

Fixed member 400 is a member fixed to a portion projecting frominsertion hole 300 h, of diffuser 210 that forms the shaft portion.Fixed member 400 is made of a resin or the like. Fixed member 400 isformed in an annular shape that surrounds diffuser 210. As shown inFIGS. 4, 5, and 13, fixed member 400 includes a locked portion 430engaged with locking portion 230. In the present embodiment, lockedportion 430 is provided as a recess that can accept locking portion 230.

As shown in FIGS. 4, 5, and 13, an outer periphery of fixed member 400is in contact with high rigidity portion 320. Namely, high rigidityportion 320 includes a fixed member receiving portion 322 that receivesfixed member 400.

As set forth above, lens 200 of license lamp 1 in the present embodimentrefracts at incident surface 211, outgoing light L1 outward in thedirection orthogonal to optical axis L0 and refracts at emission surface212, incident light L2 outward in the direction orthogonal to thecenterline of incident light L2, with respect to the centerline of theincident light. Therefore, outgoing light L1 emitted from light source100 is diffused over a wide range. Therefore, license plate 20 isilluminated over a wide range.

It should be understood that the embodiment disclosed herein isillustrative and non-restrictive in every respect. The scope of thepresent disclosure is defined by the terms of the claims rather than thedescription of the embodiment above, and is intended to include anymodifications within the scope and meaning equivalent to the terms ofthe claims.

For example, a water shut-off structure that suppresses entry of waterinto holder 300 by annular rib 312 b and flange 220 can be applied alsoto a component other than license lamp 1. In the water shut-offstructure, a member held by holder 300 is not limited to lens 200 thatfunctions as the light guiding member.

A fixing structure for fixing lens 200 functioning as the light guidingmember to holder 300 by clamping holder 300 between flange 220 and fixedmember 400 can be applied also to a component other than license lamp 1.In the fixing structure, the light guiding member held by holder 300 isnot limited to lens 200.

An exemplary embodiment described above represents a specific example ofan aspect below.

A lens according to one aspect is a lens that diffuses outgoing lightemitted from a light source. The lens includes an incident surfacethrough which the outgoing light enters the lens, the incident surfacebeing formed at a portion opposed to the light source, and an emissionsurface through which incident light incident on the incident surfaceexits from the lens. The incident surface refracts the outgoing lightoutward in a direction orthogonal to an optical axis of outgoing light,with respect to the optical axis of the outgoing light. The emissionsurface refracts the incident light outward in a direction orthogonal toa centerline of the incident light, with respect to the centerline ofthe incident light.

In this lens, outgoing light is refracted at the incident surfaceoutward in the direction orthogonal to the optical axis and incidentlight is refracted at the emission surface outward in the directionorthogonal to the centerline of incident light, with respect to thecenterline. Therefore, outgoing light emitted from the light source isdiffused over a wide range.

Preferably, the incident surface is in a shape convexly curved towardthe emission surface and the emission surface is in a shape convexlycurved in a direction away from the incident surface.

The effect above is thus advantageously achieved.

In this case, preferably, the incident surface is larger in curvaturethan the emission surface.

Preferably, the emission surface includes a main surface and an incidentangle of the incident light with respect to the main surface is set to acritical angle.

Incident light is thus diffused over a wider range when incident lightexits from the emission surface.

Preferably, the incident surface includes an end incident portion formedat opposing ends in an orthogonal direction orthogonal to a direction ofconnection between the incident surface and the emission surface and theend incident portion is in a shape convexly curved inward in theorthogonal direction.

Illumination light that exits from the emission surface is thuseffectively diffused in a front-rear direction of the vehicle.Therefore, an illuminated range of the license plate in the front-reardirection of the vehicle is larger.

A license lamp according to one aspect is a license lamp thatilluminates a license plate attached to a vehicle. The license lampincludes a light source for illuminating the license plate, the lens,and a holder that holds the light source and the lens. The holder holdsthe light source and the lens such that outgoing light emitted from thelight source is incident on the incident surface of the lens andillumination light that exits from the emission surface illuminates thelicense plate.

Preferably, the license lamp further includes a switch that is fixedwithin the holder and operated to open a back door of the vehicle.

A structure for fixing a light guiding member according to one aspectincludes a light guiding member that guides light emitted from a lightsource to a prescribed position, a holder that holds the light guidingmember, and a fixed member fixed to the light guiding member. The holderincludes an insertion hole through which the light guiding member isinserted. The light guiding member includes a flange larger in outergeometry than the insertion hole and a shaft portion connected to theflange and inserted through the insertion hole. The fixed member isfixed to a portion of the shaft portion that projects from the insertionhole and is larger in outer geometry than the insertion hole.

In the structure for fixing the light guiding member, the light guidingmember includes the flange larger in outer geometry than the insertionhole and the fixed member larger in outer geometry than the insertionhole is fixed to a portion projecting from the insertion hole, of theshaft portion of the light guiding member. In other words, the holder isclamped between the flange larger in outer geometry than the insertionhole and the fixed member. Therefore, detachment of the light guidingmember from the holder is suppressed.

Preferably, the holder includes a holding portion that defines at leasta part of the insertion hole and holds the shaft portion while theholder is in intimate contact with an outer circumferential surface ofthe shaft portion.

A gap between the shaft portion and the holding portion is thuseffectively sealed.

In this case, preferably, the holder includes a low rigidity portionincluding a flange receiving portion that receives the flange and a highrigidity portion that is higher in rigidity than the low rigidityportion and supports the low rigidity portion. The holding portion isformed from a part of the low rigidity portion.

In this aspect, for example, when external force is applied to the lightguiding member, the high rigidity portion supports the low rigidityportion. Therefore, deformation of the entire holder is suppressed. Inaddition, since the holding portion is formed from a part of the lowrigidity portion, a state of intimate contact between the shaft portionand the holding portion is effectively secured.

Preferably, the holder further includes an adjacent portion that definesa part of the insertion hole and is adjacent to the holding portion inan axial direction of the shaft portion, and the adjacent portiondefines a space between the adjacent portion and an outercircumferential surface of the shaft portion.

In this aspect, a portion of the low rigidity portion that forms theholding portion is moved into the space at the time when the shaftportion is inserted in the insertion hole. Therefore, resistance ofinsertion of the light guiding member into the insertion hole isreduced.

Preferably, the high rigidity portion includes a fixed member receivingportion that receives the fixed member.

Thus, when external force in a direction in which the shaft portion ofthe light guiding member comes out of the insertion hole is applied tothe light guiding member, the fixed member is received by the fixedmember receiving portion of the high rigidity portion. Therefore,deformation of the holding portion or a portion in the vicinity thereofis suppressed. Therefore, sealing between the shaft portion and theholding portion is more reliably maintained.

Preferably, the light guiding member includes a locking portion thatlocks the fixed member and the fixed member includes a locked portionengaged with the locking portion.

A water shut-off structure according to one aspect includes a member anda holder that holds the member. The holder includes an insertion holethrough which the member is inserted. The member includes a flangelarger in outer geometry than the insertion hole and a shaft portionconnected to the flange and inserted through the insertion hole. Theholder includes a flange receiving portion that receives the flange. Theflange receiving portion includes an annular rib in a shape surroundingthe entire circumference of the insertion hole and projecting toward theflange.

In this water shut-off structure, the annular rib comes in contact withthe flange around the entire circumference of the insertion hole.Therefore, entry of water into the insertion hole from between theflange and the flange receiving portion is suppressed.

Preferably, the flange includes a pressing portion that presses theannular rib in a direction away from the insertion hole.

In this aspect, the pressing portion presses the annular rib in aradially outward direction of the annular rib. Therefore, the annularrib is in intimate contact with the pressing portion while it is tiltedoutward. When water enters a gap between the flange and the flangereceiving portion in this state, force in a direction to press theannular rib against the pressing portion is applied to the annular rib.Therefore, sealability between the flange and the flange receivingportion is enhanced.

Preferably, the flange receiving portion includes an inner receivingportion formed on an inner side of the annular rib and an outerreceiving portion formed on an outer side of the annular rib, and adistance between the outer receiving portion and a top of the annularrib is longer than a distance between the inner receiving portion andthe top of the annular rib.

Thus, the annular rib tends to be tilted outward when the pressingportion presses the annular rib.

Preferably, the holder includes a holding portion that holds the shaftportion while it is in intimate contact with an outer circumferentialsurface of the shaft portion so as to maintain a state that the pressingportion presses the annular rib.

In this aspect, in addition to the gap between the flange and the flangereceiving portion, a gap between the insertion hole and the shaftportion is also sealed.

Preferably, the member is a lens that diffuses outgoing light emittedfrom a light source for illuminating a license plate attached to avehicle and the holder can be fixed to the vehicle while it holds themember.

What is claimed is:
 1. A structure for fixing a light guiding member,the structure comprising: a light guiding member that guides lightemitted from a light source to a prescribed position; a holder thatholds the light guiding member; and a fixed member fixed to the lightguiding member, the holder including an insertion hole through which thelight guiding member is inserted, the light guiding member including aflange larger in outer geometry than the insertion hole, and a shaftportion connected to the flange and inserted through the insertion hole,the shaft portion including a projecting portion that projects from theinsertion hole on a side opposite to a side on which the flange islocated, the fixed member being fixed to the projecting portion of theshaft portion and being larger in outer geometry than the insertionhole, and the flange and the fixed member clamping the holder.
 2. Thestructure for fixing a light guiding member according to claim 1,wherein the holder includes a holding portion that defines at least apart of the insertion hole and holds the shaft portion while the holderis in intimate contact with an outer circumferential surface of theshaft portion.
 3. The structure for fixing a light guiding memberaccording to claim 2, wherein the holder includes a low rigidity portionincluding a flange receiving portion that receives the flange, and ahigh rigidity portion that is higher in rigidity than the low rigidityportion and supports the low rigidity portion, and the holding portionis formed from a part of the low rigidity portion.
 4. The structure forfixing a light guiding member according to claim 3, wherein the holderfurther includes an adjacent portion that defines a part of theinsertion hole and is adjacent to the holding portion in an axialdirection of the shaft portion, and the adjacent portion defines a spacebetween the adjacent portion and an outer circumferential surface of theshaft portion.
 5. The structure for fixing a light guiding memberaccording to claim 3, wherein the high rigidity portion includes a fixedmember receiving portion that receives the fixed member.
 6. Thestructure for fixing a light guiding member according to claim 1,wherein the light guiding member includes a locking portion that locksthe fixed member, and the fixed member includes a locked portion engagedwith the locking portion.